Heating element



C. J. HEISER. HEATING ELEMENT. APPUCATIONFILED MAR. 5, 1921.

Patented Nov. 14, 1922..

' Patented Nov. 14, 1 922.

' UNITED STATES PATENT OFFICE.

' CHARLES J. HEISI JR, LOS ANGELES, CALIFORNIA, ASSIGNOR To PACIFIC' MANUFAC- TURING & ELECTRIC 00., A COPARTNERSHIP COMPRISING CHARLES J. HEISER, JQHN N. VAN PATTEN, JOHN M. MORRIS, AND HARRISON H.- FOG-WELL.

H ATING ELEMENT.

Application filed March 5, 1921. Serial No. 449,720.

To all whom it may concern: I

Be it known that L'GHARLES J. HEIsER, a citizen of the United States residing at Los Angeles, county of Los ngeles, and State of California, have invented a new and useful Heating Element, of which the following is a specification.

My invention relates to electric heating elements and a particular object of the invention is to provide means in such a heating' element for reinforcing the element at the point where it is most likely to be mechanically damaged or to burn out. In

all sorts of electric heating devices, high re-' 16 sistance wire or strip is used which is disposed on the interior of the device. The

ends of the high resistance wire or strip are ordinarily brought outside the heated zone of the device for connection to low resistance conductors. Since it is impractical to make the high resistance wire or strip of variable cross section or variable conductivity, it has a substantially uniform resistance per unit length with the result that it heats uniformly both inside theheater where the heat is desired and in that portion of the wire commonly called the leads which extend from what may be termed the active portion of the heater up to the point where 80 electrical connection is to be made to the low resistance conductors. Since heaters are ordinarily manufactured to su ply heat at a certain point, thisheating o the lead wires .is often a great disadvantage due not 85 only to the loss of energy ,in the leadwires but also due to the fact that these lead wires often pass through material or 7 through places where this heat cannot be readily taken care of.

, It is an object of my invention to provide a heating element which is initially of uniform cross section but which is reinforced in such a manner that its conductivity is greatly increased in the lead pertion with the result that the heat is concentrated where needed and heating of the lead wires is prevented.

Referring to the drawing which illustrates one form of my invention,

Fig. 1 is an external view thereof.

Fig. 2 is a section.

Fig. 3 is a section through the line 3-3 of Fig. 2, and,

Fig. 4 is a section through the line 4-4 of Fig. 1.

Fig. 5 i s an enlarged section of a portion of the resistance element. 7 1

In this form of heater which is selected merely for illustrative purposes, 11 is a metal sheet sheath inside which a resistance wire 12 is supported in suitable insulation 13. The active portion of the heater may be considered as extending through that portion des gnated by the dimension A, the upper portion B being intended to be out of contact with the liquid or other material to be. heated. It is, therefore, desirable that the heat should be concentrated in the portion A and that the leads should heat very little in the portion B. For'the purpose of accomplis ing this I reinforce the materlal 12 in the portion B with a covering of high conductivity material 14. This ma. terial is preferably copper and may be electricallv deposited on the end of the wire 11 before the heater is assembled. By depositing a heavy copper coating on the outside of the wire 11, I provide the necessary conductivity so that the heating is practically negligible in the lead portion B and so that the resistance wire is mechanically reinforced at this point. By running the lead portion cold and b increasing its diameter and strength by t is electrically deposited coating of copper, I do away with many of the mechanical troubles found in all sorts of electric heaters.

I claim as my invention:

1. In an electric heating device, the combination of a heating element situated in said device and having a lead projecting therefrom; and a reinforcing conducting coating secured about and .in electrical contact with said lead.

2. In an electric heating device, the combination of a heatin element situated in said device and having a lead projecting therefrom; and a reinforcing conducting coating plated upon the outer surface of said lead. V

3'. In an electric heating device, the combination of a heating element situated in said device and having a lead projectin therefrom; and a high conductivity meta ileelve plated upon the outer surface of said 105 4. In an electric heating device, the comsistance' metal situated in said device and bination of a heating elementof high rehaving a lead projecting therefrom;and a 10 sistance metal situated in said -device and high conductivity metal sleeve plated upnn having a lead projecting therefrom; and a the outer surface of said lead.

5 reinforcing conducting coating plated upon In testimony whereof l have hereunto the outer surface of said lead. set my hand at Los Angeles, Gali'fornia,

5. In an electric heating device, the comthis 25th day of February, 1921.

bination of a heating element of high re- 1 CHARLES J. HEISER. 

